Disk motor with bearing prestressing feature

Abstract

The invention relates to a disk motor with an armature disk, which is rotatably mounted and provided with permanent magnets, and with a stator which comprises a stator plate which is equipped with coils. The aim of the invention is to provide a disk motor that is as flat as possible and that is characterized by an improved smoothness of running. To this end, an annular soft-magnetic prestressing device is arranged concentrically on the stator plate in such a manner that at least one section of the prestressing device is located below the coil window of the coils in the axial direction. The armature disk may support an annular flux-return element opposite which the annular prestressing device is located in the radial direction. Said prestressing device has a cross-sectional contour that guides the magnetic lines of electric flux from the annular flux-return element to the coil window.

Description

DESCRIPTION1. Field of the InventionThe invention relates to a disk motor with an armature disk (3), which is rotatably mounted and provided with permanent magnets, and with a stator comprising a stator plate which is equipped with coils.2. Background of the InventionSuch disk motors are used as direct drives for turntables, for example. A basic explanation of disk motors can be found in H.-D. Stolting, A. Beisse, Elektrische Kleinmaschinen, Verlag Teubner, 1987, p. 169ff and p. 186ff.DE 34 25 805 A1 discloses a DC motor realized as a disk motor to rotate a mirror. The stator comprises a coil-insulating frame and a stator flange connected thereto, which flange completely encloses the rotor and protects it from external influences. The rotor has a shaft which is attached to the mirror and which has on its lower end a magnet holder equipped with a two-pole permanent magnet. The rotor shaft ts punted in two ball bearings secured in the stator flange. To minimize axial play, the outer r...

AI Technical Summary

Problems solved by technology

The disadvantage of this arrangement, however, is that there are two ball bearings arranged one above the other and separated by some distance.

This disk motor has the following disadvantages: first there are two ball bearings with the associated additional assembly / installation costs; and second, the flux-return circuit does not run exclusively through the active region of the coils and thus does not contribute wholly to the generation of torque.

Furthermore, attractive force is exerted on the armature disk in both the skirt region and the hub region, thus very large forces are exerted on the armature disk and in turn the bearings; significant bearing loads can result which under certain circumstances can lead to premature bearing failure.

The motor is heavy as a result.

This prevents the lines of electric flux from running over the bearing, which would adversely affect running smoothness.

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